Pressure lock key



J. w. GILLEN 2,681,239 PRESSURE LOCK KEY Filed Aug. 16.` 1950 y WQI@ a @7a/g2g Patented June l5, 1954 UNITED STATES PATENT OFFICE PRESSURE LOCK KEY James W. Gillen, Riverside, Ill. Application August 16, 1950, Serial No. 179,819 s claims. (o1. esi-52.05)

My invention contemplates and provides a new and improved key for securing wheel hubs and the like to the shafts Whereon they are mounted.

A salient object of my invention is to eliminate the necessity for accurate milling or broaching of those slots in a wheel hub or the like and its shaft which. when such parts are being secured together, are brought into immediate juxtaposition and alignment for the reception of a key that is to lie within both the shaft and the wheel hub or the like while extending axially of the same. Accurate machining of such key slots is an expensive operation desirably to be avoided.

Another object of my invention is to provide improved keys for reception by the juxtaposed and aligned axially extending slots formed in shafts and wheel hubs and the like such as gears, pulleys, sprockets, etc.

A pressure lock key of my instant invention is an elongated metal of its opposite longitudinally extending faces, i. e. its faces that ultimately are to be presented to the bottoms of key slots in a wheel hub or the likeand its shaft', has had pressed lengthwise extending V-shaped grooves with the effect of distorting a major portion of such element from an initially generally square or oblong cross-section that is substantially but not quite entirely re-assumed when such element has been appropriately driven home into said key slots.

Other objects, features and advantages of my novel pressure lock key will appear rom the following description of presently preferred forms thereof wherein reference is made to the accompanying drawings in which,

Fig. 1 is a perspective view of a tapering form of `my pressure lock key;

Fig. 2 is a cross-sectional view that may be regarded as taken in the transverse plane of the line 2-2 of Fig. 1 and looking in the direction indicated by the arrows;

Fig. 3 is an elevational view of the left end of the key shown in Fig. 1;

Fig. 4 is a section of parts of a wheel hub or the like and its shaft that have been secured together by the pressure lock key of the preceding figures;

Fig. 5 is a perspective view of a generally straight form of my pressure lock key;

Fig. 6 is a cross-sectional View that may be regarded as taken in the transverse plane of the line 6-6 of Fig. 5 and looking in the direction indicated by the arrows;

Fig. 7 is an elevational view of the left end of the key shown in Fig. 5;

element which into two Fig. 8 is a perspective View of a somewhat large tapering form ot my pressure lock key;

Figs. 9 and l0 are, respectively, elevational views of the right and left ends of the key depicted in Fig. 8; and

Fig. 11 is a perspective view of a somewhat large gib head form of my new pressure lock key.

Similar' reference numerals refer to `similar parts throughout the several views.

Referring rst to Figs. 1, 2 and 3, reference numeral l5 denotes a tapering form of my novel pressure lock key. Originally it was in the form of an elongated metal (preferably steel) bar of generally rectangular (preferably square or oblong) cross-section having parallel opposite longitudinally extending faces, the cross section being uniform in size throughout the length of the bar. However, there have been pressed into opposite longitudinally extending faces of such bar V-shaped grooves indicated at lli-i6. Such grooves desirably extend lengthwise and medially of the surfaces into which they have been pressed. They gradually diminish in both width and depth from one end (the right end in Fig. l) of the key to points spaced from the other end thereof. Such key end of which the grooves |$-56 stop short retains its original rectangular cross-section, as revealed in Fig. 3, but the formation of the grooves 6-|6 has distorted the other end of the key substantially as revealed in Fig. 2, the degree of distortion being a maximum at the end of the key to 'which the grooves IIS- I6 extend and disappearing at the region spaced from the other end of the key where such grooves cease to exist.

By saying that the grooves IB-l are pressed into the key l5, I mean that they are formed, as with a suitable grooving roller, by the displacement but not the removal of metal of the key. The resultant distortion of the key has brought about increases in both the overall height and the overall width of the key where the distortion occurs.

In Fig. 4, I have indicated at il a shaft whereto a wheel hub or the like I8 has been secured by one of my novel pressure lock keys l5. The parts l1 and i8 have been provided with conventional axially extended aligned key slots Ila and lBa, both of which are occupied by the pressure lock key l5. However, because of the novel characteristics of the pressure lock key, it is unnecessary that the slots lla and 18a be accurately correspondingly machined as would of those keyways.

be necessary were a conventional key utilized in conjunction with such slots.

In associating the pressure lock key l5 with the aligned key slots Ha and 18a, the undistorted end (left end of Fig. 1) of the key is inserted into such slots. The key is then driven to its functioning position in such slots. As and when the key is driven home to such functioning position its distortion, occasioned by the pressing Y into the key of its grooves l6-i6, is largely but not quite eliminated, as indicated in Fig. e. In other words, as an incident to such driving home of the pressure lock key, the sides and bottoms of the slots lla and Ita, forcibly Contact the opposed surfaces of the key to cause metal of the key to assume very nearly its original disposition and contour. As the key substantially reforms against the walls of the slots into which it is driven it develops, within the elastic range of its metal (preferably steel) an effective holding pressure against the walls of such slots even though the latter have not been accurately and/or correspondingly machined.

A key, tapering as does the one just described, that can be utilized effectively in conjunction with opposed keyways having substantially parallel side walls, and that will automatically adjust itself to the variations in width and depth tolerances of those keyways, is a novel and problem-solving machine part. Heretofore, when utilizing a taper key in conjunction with opposed keyways it has been the practice to try to broach one Vor both of those keyways to an accommodating taper.

The pressure lock key i9 of Figs. 5, 6 and 7 differs from the key l5 of the preceding figures in that its pressed-in grooves dii-29 are of substantially uniform depth and width throughout their lengths. Key i9, therefore, lacks theY taper that characterizes key l5. In key i9, however, as in key i5, the pressed-in grooves extend from one end of the key to points spaced from the other end thereof, with the metal at such other end of the key remaining undistorted by the formation of the grooves. In associating the pressure lock key i9 with cooperating opposed key slots, the undistorted end of such key (In Fig. 5 the left end) is first inserted in such slots. Then the key is driven home to its functioning position in those slots. As and when thus driven home it, like previously discussed key I5, automatically adjusts itself to the variations in width and depth tolerances of its associated keyways.

ri'he pressure lock key 2i of Figs. 8,V 9 and 10 differs essentially from previously discussed key l5 only in that each of those faces of the key which are to be presented to the bottoms of its associated keyslots or keyways is provided with two spaced-apart and generally parallel pressedin grooves 22-22- Here again we have a key that tapers lengthwise, that has an undistorted end (in Fig. 8 the left end) for placement in the keyways whereinto the key is to be driven, and which when driven home automatically adjusts itself to variations in Width and depth tolerances The pairs of grooves 22-22 usually will characterize keys of comparatively large cross-section.

The pressure lock key 23 of Fig. 11 differs materially from previously discussed key 2l only in that it is provided with. a gib head 24, for a well-understood purpose, at its end wherefrom its grooves 25--25 diminish in width and depth. Here we have a gib head key that tapers lengthwise that has an undistorted end for placement the displaced f* ments, said key comprising a 4 in the keyways whereinto the key is to be driven, and which when driven home into those keyways automatically adjusts itself to variations in width and depth tolerances of those keyways.

Other specific forms of my novel pressure lock key will suggest themselves to persons skilled in the art whereto my invention relates.

The novel pressure look key of my invention is economical to manufacture, easy to install, capable of re-use, and is of great practical importance and value because it greatly liberalizes the tolerances with which manufacturers are required to mill, broach or otherwise machine the opposed keyways with which the key is to cooperate. y

Having thus illustrated and described several practical illustrative embodiments oi my invention what I claim as new, and desire to protect by United States Letters Patent, is:

i. A pressure lock key for insertion into opposed Vstraight-sided key slots, said key comprising a metal bar having two opposed drive transmitting sides whichare concave and are adapted to contact the straight sides of the key slots at the edges of said concave sides, and having two opposed sides connecting the concave sides, each of said opposed connecting sides one groove formed therein Vand extending longitudinally of the bar, said groove providing a space into which the metal of the bar included betweenA the grooves and the edges of the concave sides is adaptedY to move as the key is inserted under pressure into said opposed key slots to provide a tight iit between the key and its key slots in the direction of drive.

2. In combination, rotatable driving and driven machine elements, one of said elements being received within the other and each ofV said elements having a straight-sided key slot, the key slot of one element being aligned with and opening into the key slot of the other element and defining between them a substantially rectangular opening, and a pressure lock key in said opening for drivingly connecting the vmachine elemetal bar having two opposed drive-transmitting sides which are concave and contact the straight sides of the key slots at the edges of the concave sides and havingl two-opposed sides connecting the concave sides, each of said opposed connecting sides having at least one groove formed therein and extending longitudinally of the bar, said groove providing a Vspace into which the metal of the bar included between the grooves andthe edges of the concave sidesv is moved as the key is inserted under pressure into said opposed key slots to provide a tight fit between the key and itsV key slots in the direction of drive between the elements.

3. The combination as described in claim 2, said groove being tapered in width. to provide a tapered lkey for ready insertion into a key slot. References Cited in the le of this patent UNITED STATES PATENTS Number Y Name Date- 1,163,276 Sperling Dec. 7, 1915 1,219,978 Masters Mar. 20, 1917 1,439,769 Smith Dec. 26, 1922 1,460,222' Benjamin June 26, 1923 2,251,202 Purtell July 29, 1941 2,401,967 Sandberg June 11, 1946 FOREIGN PATENTS Number Country Date 502,719 Germany Jul-y 17', 1930 having at least, 

